According to MMAFighting.com's Ariel Helwani, "The American Gangster" tested positive for four different banned substances in his latest drug test. Sonnen submitted to a random drug test on June 5 upon request from the Nevada State Athletic Commission, in advance of his then-upcoming bout with Vitor Belfort at UFC 175.

Sonnen retired from MMA earlier this month following his failure of a separate drug test, where he tested positive for anastrozole and clomiphene. While some were quick to defend his use of the drugs due to the sudden ban on TRT from the Nevada State Athletic Commission, the addition of EPO and HGH is far more difficult to defend.

EPO is a hormone commonly used to increase the concentration of red blood cells, which improves stamina, cardio and endurance during athletic competition. Both EPO and HGH are frequently associated with Major League Baseball's BALCO scandal, where high-profile players like Jason Giambi and Barry Bonds obtained the drugs to aid their in-game performance.

Anastrozole and clomiphene are both estrogen blockers and are commonly used by men in sports to jump-start natural testosterone production following use of anabolic steroids, which can diminish the body's ability to produce the hormone. HCG can also be used to reinvigorate testosterone levels, and fans may remember UFC featherweight Dennis Siver was recently suspended for the drug.

All five of the drugs Sonnen has tested positive for between the two tests are banned out of competition.

Needless to say, this will have a clear impact on his legacy, and it lowers his chances of making a possible return later this year. There is no word yet on when Sonnen or UFC President Dana White may make a statement on this, but stick with Bleacher Report for more details as they become available.